Air supported cleaner with control



June 19, 1956 ACHESON 2,751,038

AIR SUPPORTED CLEANER WITH CONTROL Filed May 14, 1954 4 Sheets-Sheet 1 40 i 90 96' 24 5 5: 95 97 I E r 2 9/ I 95 92 3/ 25 27 2/ l2 m /7 N g? 5/ VII/,1 /5 47 I t I! /3 7 52 i v 4 e7 77 76 V //0 Q 88 //6 H3 72 a0 79 June 19, 1956 L. K. ACHESON AIR SUPPORTED CLEANER WITH CONTROL 4 Sheets-Sheet 2 Filed May 14, 1954 June 19, 1956 K. ACHESON AIR SUPPORTED CLEANER WITH CONTROL 4 Sheets-Sheet 3 Filed May 14, 1954 Fig.3

J1me 1956 L. K. ACHESON 2,751,038

AIR SUPPORTED CLEANER WITH CONTROL Filed May 14, 1954 4 Sheets-Sheet 4 United States Patent AIRSUPPORTED CLEANER wrrrt CONTROL Louis K.v Acheson, North Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a corporation ofOhio Application May 14, 1954, Serial'No. 429,940.

12 Claims. (Cl. 183-37) My invention relates tocleaning apparatuses of the so-calledtank or canister type-wherein the cleaner is'provided with means by which it can be supported upon an air cushion or bearing and is so arranged that the air cushion or hearing is rendered operative or inoperative atthe will of the operator in a very simple manner.

My-invention relates generally to the class of apparatus disclosed'and claimedin application Serial No. 418,512, ofCurtis-C'. Coons and John C. Montgomery, filed March 25, 1954, entitled Air Supported Cleaner and represents animprovement-thereover.

The aforesaid application discloses a suction cleaner which is supported upon an annular surface-engaging member combined with an arrangement for conducting exhaust air under pressure from the cleaner structure into the space or plenum chamber between the cleaner and the periphery of the supporting structure whereby the air pressure builds up in the said space to form an air cushion or hearing which supports the entire weight of the cleaner whereby-the same may be moved across the supporting surface in response'to the application of a very small force thereto as the-air bearing or air cushion support islsubstantially frictionless.

In apparatusconstrueted according to my invention, the air bearing or air cushion supporting structure is rendered operative or inoperative at the will of the operator and the cleaner isrelieved of the back pressure developed'by' the air bearing except atsuch time as the same is actually in use for facilitating movement of thecleanenon-thesupporting surface.

In accordance with one form of myinvention, the cleaner proper and its casing-isprovidediwitlr'one'exhaust portwhich is always'open to the aircushion or plenum chamber and -'one or more additional air exhaust ports ex hausting air into the surrounding air or'into an exhaustdif fusing structure having substantially negligible bacl's pressure.- A'- slight tug on the suction hose'in-any direction automatically shifts one part ofthe-oleanerwith referenceto another to close-thenormalexhaustport and-"diffusing structureand to cause all the air-to p'ass'to -the-air hearing'or plenum chamber sothat the cleaner-moves across the floor with the-greatest of ease;

In a modified form of my invention: the conversion frornfreeexhaust to an exhaust diffusing structure to an air;

section and illustrating the condition of. the. apparatus when a-slight pull is appliedto the suction hose;

Figure 4 is a fragmentary developed. vview to. illustrate,

ICC

2 the relationof certain exhaust-ports andthe" control structrite-therefor;

Figure 5 is a sectional view of the bottom portion of a suction cleaner embodying a modified form of the invention; and- Figure'o' is a view taken along the line 66, of Figure 5 and looking in the direction of the arrows;

Referring now to the" drawing in detail and first: to Figure 1 thereof; the suction cleaning apparatus there illustrated comprises an inner andgenerally sphericalc'asing 1 which is composed ofupper and lower, substantially hemispherical sections 2- and 3, respectively, which are hingedly connected atone side by a hinge 4 and are joined at their opposite sides'by a suitcase latch type clamp 5. The lower'hemispherical section 3 is internally provided with a bulkhead-7 which is imperforate except for a central opening 8 through which projects a conventional type of suction cleaner power plant'comp'rising a suction fancasing 10having an'electricdrive" motor'll joined thereto and'depending therebelow. As seen in Fig: ure 1 the power plant substantially fills the opening 8. The power plant is provided with a peripheral flange 12 which is engaged between a pair of mating, cushioning and mounting rubber gaskets 13 resting upon the bulkhead 7 around the periphery of the opening 8. A secondary filter structure overlies the upper end of the fan casinglO and-1 comprises a sheet-like filter member 19 stretched over a cylindrical support with'an inwardly-curved-upper end defining an opening 17 spaced above the air inlet 18 of the fan casing 19. The support 16- has an annular flange- IS resting on gaskets 13 The flange and gaskets 13-are'auchored to the bulkhead 7 by bolts 14. The power plant 11 is of a well-known type in which the suction air enters the fan casing ltlthrough the inlet 18, passes through one or more fan stages and then exhausts around and through the motor housing 11 to the underside of'the-bulkhe'ad 7 from whence it is exhausted ina manner to be'described hereinafter.

The upperedge of easing section Sterminates in an inwardly-turned narrow flange'20 upon which is mounted a sealing gasketll which is'abutted by an inwardlyturned flange 22" on the lower part of the upper casing section a 2.

The top central portion ofthe upper casing 2 is formed with-an opening to receive a hose connecting sleeve'collar 23 which isformed with an inwardly-directed and down-turned annular flange 24 at its outer end for a purpose to bedescribedhereinafter; The inner portion of the' sleeve' 23 is telescopically received in an enlarged diameter section 25 of a filter mounting collar 26 which is-formedat itsupp'erouter end with a laterally-directed fi'an'ge-27secured to theinner face of the casing section Z'by spot weldingor the-like. The sleeve 23 is rigidly secured tothe enl'arg'edsection 25 of the mounting collar as byspot welding.

A fi lte'r30; which'maybe of paper or cloth as desired, is' mo'untedirr the upper section of the inner casing 1 above the power plant structure and secondary filter 19 and is providedwith a narrow' inlet' neck' 31 shaped to receivetheproj'ecting; portion of the filter mounting collar 26 and-is secured'thereto as by a garter spring 33 forcing the; filter int'o. an" internal :bea'd 34' formed in the mounting to 25.

The sleeve 23 and collar 26=receives a cylindrical connectings' conduit 35 forming one leg of ahose-connectingv elbow" 36 wh-ich= is-prov-ided with a laterally-projectingv cated by the reference character which includes a tongue portion 41 projecting into the space within the sleeve 23 underlying the flange 24 so as to releasably and rotatably connect the elbow 36 to the sleeve 23 and to direct air and dirt pulled through the cleaning tool 39 and hose 38 into the filter 30.

The inner cleaner casing 1 is housed within an outer, generally spherical casing which is formed of an upper, generally hemispherical member and a lower, generally hemispherical member 46. The hemispherical member 46 carries a cushioning gasket 47 at its upper end which is engaged by an outwardly-projecting annular flange 48 on the lower end of the upper casing section 45. The casing section 45 is provided with a resilient circumferential bumper 50 which is mounted over and secured to the flange 48. The flange 48 carries a pair of downwardly-directed, hook-shaped secured latch members 51 on opposite sides of the casing 45 which are adapted to be engaged by toggle latch members 52 to secure the casing halves together with the gasket 47 com- L 1 is also guided and supported within the outer casing at I its upper portion by means of an upper set of bearing balls 62 which are carried by leaf springs 64 secured to the inner face of the upper casing 45. The leaf springs 64 are so biased with respect to the upper casing section 45 that they tend to move inwardly and press the bearing balls 62 against the outer surface of easing 1 and seat the same firmly upon the lower bearing balls 61. The ball bearing mount supports the inner casing so that it has a slight clearance with the small diameter portion of casing section 46 and the inner casing 1 is free to move in all directions with respect to the outer casing from the neutral or normal position illustrated in Figure 1.

in the operation of the device, cleaning air passes through the filter and over the power plant unit to cool the same and then discharges into that portion of the casing beneath the bulkhead 7 and normally exhausts therefrom through a plurality of exhaust ports 65 which are aligned with matching exhaust ports 66 formed in the lower. reduced-diameter portion of the outer casing section 46.

The bottom portion of the section 46 is provided with a large diameter central opening defined by a cylindrical flange 68 which is welded or otherwise secured to a flange 69 on. a spherical segment 71 spaced from the reduced diameter portion of casing 46 to define an annular exhaust and diffusing duct 72 therewith. The ports 66 open into duct 72 which discharges exhaust air in an annular, upwardly-directed and ditfused stream. The upper end of segment 71 joins a downwardly and outwardly-flaring conical segment or member which rests upon an annular inwardly-extending flange 75 joining an upwardlystepped flange 76 which terminates in an upwardly-directed conical segment 77. The conical segment 77 abuts a second conical segment 78 which is formed as a cone of greater angle than the conical segment 70 and termimates in. a flange 79 underlying the step portion 76 so as to be aligned with the portion 75 of the conical segment 70. The upper end of the conical segment 78 bears against the lower end of the spherical segment 71 and is held in the foregoing assembled relation by means of self-tapping studs 86, for example, extending therethrough and threading into the conical segment 77.

The supporting structure forms the peripheral boundary of a space or plenum chamber which is vertically bounded by the underside of the cleaner casing 3 and a supporting surface. The space or plenum chamber 85 forms the air cushion or air bearing for supporting the cleaner as will be explained more fully hereinafter.

The lower central portion of the casing section 3 is provided with an exhaust conduit 86 secured to the bottom thereof and opening to the space within the casing 3 beneath the bulkhead 7. Outwardly of the casing 3 the conduit 86 has an enlarged diameter cylindrical section 87 terminated in an inwardly and upwardly-directed flange 88 to form an anchoring flange to receive a securing latch such as the latch 41 when the cleaner is to be converted for blowing operation.

The elbow receiving collar 23 loosely and slidably receives a cylindrical collar member 90 which at its lower end terminates in an outwardly directed annular flange 91 forming an anchor for three equally spaced lightweight tension springs 92 having their inner ends secured in suitable anchoring holes 93 in the flange 91. The outer ends of springs 92 are anchored by studs 94 which project inwardly and downwardly from a horizontal annular flange section 95 which is carried by a cylindrical section 96 of the upper casing section 45. The annular flange 95 joins an upwardly and inwardly directed conical annular flange 96 which terminates in a short downwardly directed barrier flange 97 forming a large diameter opening surrounding the collar 23 in spaced relation thereto. The tension springs 92 normally maintain the collar 23 in the position thereof illustrated in Figures 1 and 2 in which event the exhaust ports 65 and 66 in the casing sections 3 and 46, respectively, are aligned and all air exhausted from the cleaner has a free passage to the outside through the ports 65 and 66 and diffusing throat 72.

When the user desires to obtain access to the filter the elbow 36 is first disengaged from the collar 23 after which the clamps 52 are released from the latch 51 and the outer casing section 45 is lifted vertically away fromthe inner casing and outer casing section 46. During such lifting operations the cylindrical guide collar 90 slides upwardly on the collar 23 until it is free of the same at which time the entire upper casing section is removed. Thereafter, the clamp 5 can be released and the casing section 2 can be pivoted away from the casing section 3 to allow the user to obtain access to the filter for cleaning or replacement thereof whichever may be desired. The reverse operations are performed in reassembling the cleaner.

When the cleaner is in use the normal condition is illustrated in Figure 1, wherefore the exhaust air all passes through the throat 72 to be diffused into the atmosphere. This provides an exhaust air flow path of minimum resistance to allow the cleaner to operate at maximum efliciency. It will be appreciated that the elbow 36 is free to rotate through a 360 are within the collar 23 since it is held thereto by the tongue 41 only against axial displacement. However, should the user of the cleaner want to move beyond the normal distance provided by the flexible hose 38, a slight pull on the flexible suction hose 38 will overcome the force of the springs 92 causing the inner cleaner casing to shift slightly in the ball support to a position such as that illustrated in Figure 3..

Under these conditions the ports 65 and 66 are not aligned and all the exhaust air passes through the fitting 86 to the space or plenum chamber 85.

A typical position of the exhaust ports 65 and 66 is illustrated in Figure 4. When the hose 38 has been subjected to a pull to rock the inner cleaner easing 1 with respect to the outer casing structure, the inner casing shifts so that the exhaust ports 65 and 66 are no longer aligned and exhaust air does not flow therethrough.

In the normal position of the parts illustrated in Figure l the ports 65 and 66 are aligned and the vertical center lines of the inner and outer casings coincide. When the inner casing is rotated on its ball mount in response to a tug applied to the hose 38, the foregoing center lines assume an angular relation to each other wherefore the traces of the center lines in a horizontal plane through a point just above the ports 63 assume the position illustrated in Figure 4; that is, the center line trace of the outer shell is represented by the dot 120 whereas the center line trace of the inner shell is represented by the dot 121 indicating that the two shells have been moved to produce an eccentricity represented by the dashed line 122. Under these conditions each of the ports 65 has been shifted from its previous position by a distance which is greater than its diameter wherefore it no longer coincides in any particular with its normally associated port 66. In order for this type relationship tobe assured under all conditions, or in response to a pull on the hose 38 in any direction, the distance between adjacent ports 66 and adjacent ports 65 is greater than the diameter thereof so that no port 65 will be moved from a position oftotal or partial registry with one port 66 into a position of partial registry with an adjacent port 66. The springs 92 are light but are sufficient in strength normally to maintain the inner shell in the position illustrated in Figure 1 relative to the outer shell, however, the equidistant spacing of these springs is so chosen that a light pull on the hose 38 in any direction will shift the inner shell in the direction of the pull relative to the outer shell sufficiently to disengage or to destroy the alignment or overlapping relation of ports 65 and 66 completely, The trace of the circle illustratedby the dashed line 124 in Figure 4 illustrates all possible positions of the trace of the center line 121 with respect to the trace of the center line 126 from which it will be seen that movement corresponding to the line of eccentricity 122 in any direction through a complete 360 arc will produce the desired misalignment of ports 65 and66 resulting in cornpl ete closure of the ports with respect to air discharge therethrough. A dashed line 125 similar to the line 124 has been drawn around the trace of one of the ports 66 to illustrate all possible positions of the center line ofthe corresponding port 65. It is apparent from the position of the line 125 with reference to the concentric port 66 that the port 65 will always be completely out of alignment with the ports 66 in all positions of the port 65 on the construction line 125.

In the operation of this device the operator is normally using the cleaning tool 39 with a slack in the hose and is free to move about the cleaner into any angular position with respect thereto due to the swivel mounting of the hose connecting elbow 36. However, should the opera tor begin to move out towards the extremity of the hose length provided, a translatory force will be transmitted through the hose, either by unconscious movement of the operator away from the cleaner or by a conscious pull applied thereto resulting in shifting the inner shell-to some position such as that illustrated in Figure 3 of the drawing whereupon all of the air discharging from the power plant unit flows through the hose connecting member 8687 into the air cushion space or plenum chamber 85.- The projected area of space or plenum chamber 85 is large, hence a small back pressure in space or plenum chamber 85 is sufficient to support the entire weight of the cleaner structure, lifting the same as is shown in exaggerated form in Figure 3 so that it is supported com-. pletely upon a hearing or cushion of air. It has been found that a cleaner so supported upon a cushion or bearingof air may be moved across a supporting surface for a large. distance in response to a very slight push or pull applied thereto which is negligible compared to the force which is normally required to move a cleaner across a surfaceagainst the frictional drag of the supporting surfaces.79-75. As soon as the cleaner has moved a substantial distance, the hose becomes slack and the springs 92 then restore the inner casing to the position illustrated in Figure 1 Which relieves the space 85 of air pressure because all" air new exhaust: through the throat 72.

The foregoing operation is highly desirable because in.

normal usage the cleaner is subjected to negligible back pressure and no air is discharging parallel. to the supporting surface under the bearing surfaces 79 and 75. Air so discharging is somewhat objectionable because it tends to blow surface litter and dust along therewith whereas air discharging through the throat '72 is above the supporting surface and upwardly directed with the result that such air has. no objectionable effects. Additionally, the small back pressure produced by the air cushion or bearing detractsto some extent from the efliciency of the cleaner. In accordance with the present invention, this. slightly undesirable feature is always eliminated except for rather short periods of time as the cleaner is actually being moved from place to place.

In order to convert the. apparatus to blowing operation the hose is disconnectedfrom. the collar 23 and connected into the collar 88 after the cleaner has been rockedon its side to expose that member. Under such circumstances, it is desirable to have all of. the air directed through the hose connection 8687. Accordingly, the inner cleaner casing is rocked to a position such as; that. illustratedin Figure 3 and is secured:in .that position by means of a latch mechanism consisting. of a latch keeper arm projecting downwardly fromthe underside of. thecasing section 3 into thea-ir pocket space 85. The member 110 is adapted to beengaged by a bail member 111- which is pivotally connected to a. toggle arm 112 pivotally supported on a pintle. 113. carried by the underside of the plate 78. The toggle. arm.112. is. biased to a fixed position by meansof aspringll i-which is connectedat one end to a lug 115mounted on the conical member 70 and atits other end to alug116welded to theunderside of the member 112. As. is apparent from Figure- 1, the spring 114passes through asuitableopening 117 formed in the member. 78. When the bail- 111 is. engaged with thelatch110 thepartsof the cleaner casings are retained in the position .illustratedin Figure 3 in which position all air dischargedby the. circulating fan flows through the connecting. member 8687 and the. suction hose connected thereto.

Referring now. to Figures 5 and 6, a modified form of theinvention is illustratedwhichis.less automaticthan that disclosed hereinabove. but is considerably. simpler instructure. Those portions of the apparatus of Figures 5 and 6v which are identical with corresponding portions of the apparatusheretoforedescribed in connection with Figures 1 to .4 are .giventhesamereference character distinguished by the addition of a prime. ln this form of theinvention. only. asingle casing is provided as relatively rotating casingstructures are not utilized. Only the lower portion of the apparatus is illustrated. The cleaner casingv 1 is fixed and has a lower section 3 The casing 1 forms the entire housing. and supporting structure for the motor unitdl' and the uuillustrated filter mounting, fan housing, hose. connector and power plant supporting structures exactly as is illustrated in Figure l with reference to the structures for supporting these parts in. the casing 1. Also, the casing. 3' isnot formed with. holes 65 as. is the. casing 3- for reasons which will become. apparent. hereinafter.

The lower portion of thecasing-3 mergers into a downwardly-extending, rather short-length, cylindrical section which is provided with a plurality of spaced-apart exhaust, ports 151and. is closed at its bottom by a disclike plate 152. The exhaust fitting 85-87"-88' is mounted in the centerof plate 152.; The surface-supporting structure for the cleaner of. Figures 5 and'6 comprisesa generally conical section wall member 155, the upper end of which is provided with adownwardly and inwardly-directed flange 156 secured to the underside of the casing, 3' by studs 157. The upper portion of the Wall is provided Witha plurality of elongated, spacedapart exhaust ports 158. The. lower portion of theconical supporting wall 155 terminatesv inan inwardly-directed, hor izontaL, annular supporting flange 159 which-is adapted;

to engage and support the cleaner structure upon a supporting surface. The flange 159 terminates in an upwardly and inwardly-directed, short, conical flange 160 which abuts a corresponding annular flange 161 on an interior annular wall 162. The flanges 160 and 161 are secured in assembled relation by studs 163. The wall 162 terminates at its inner end in an upwardly-directed, short, cylindrical flange 164 which is telescopically rereceived within a complemental flange 165 depending from the horizontal portion of an annular stop 166 formed on the inner end of a downwardly and inwardlydirected conical wall 168 which terminates at its upper end in a flange 169 welded to the inner face of the conical supporting wall 155 below the level of the exhaust ports 158.

The depending structure 15(l152 is surrounded by a control valve structure comprising a bottom plate 170 rotatably mounted on the exhaust fitting 86'. The outer edge of the disc 170 carries an upwardly-directed cylindrical flange 172 which is provided with a plurality of spaced-apart exhaust ports 173 corresponding to the ports 151. The cylindrical wall 172 supports a short outwardly-directed arm 174 to which is welded a pedal or actuating arm 175 extending through an exhaust port 176 in the conical wall 155. The port 176 is identical with the ports 158 except that it has a considerably greater circumferential length as is shown in Figure 6 in order to accommodate the projecting arm 175 to allow the arm 175 to extend to the outside of the cleaner structure where it is readily accessible for engagement by the operators foot or hand to rotate the disc 170 and its connected parts. When the exhaust ports ISL-173 are aligned as illustrated in Figure 5 all air exhausting from the cleaner structure flows through these ports into the space between the conical wall 168 and underside of the cleaner casing 3' and thus exhausts through the openings 158-176 to the outside. It is apparent that the air passageway thus formed is of large cross section so as to afford negligible air flow resistance to avoid generation of back pressure on the motor and fan assembly of the cleaner. The position of the ducts 158 at the upper portion of the conical wall 155 causes the exhaust air to be directed outwardly and upwardly of the cleaner body in spaced relation to the supporting surface in a circumferential, comparatively low velocity and diffused air stream. When the arm 175 is operated to actuate the member 170 and its associated parts away from the position illustrated in Figure 5 to the opposite end of its arc of movement allowed by the length of the exhaust port 176, the openings 173 are so shifted relative to the openings 151 as to be blocked with respect to each other and prevent flow of air therethrough, consequently, all air exhausted by the motor fan unit flows through the fitting 86' into the space or plenum chamber beneath the cleaner housing and within the supporting structure. Under these circumstances, air pressure builds up within the space or plenum chamber on the underside of the cleaner and Within the supporting structure sufliciently to counterbalance the weight of the cleaner, whereupon the air exhausts laterally of the cleaner under the surface 159 to form an air bearing or cushion upon which the cleaner is supported and which will. allow the same to be moved about a supporting surface with the greatest of ease.

In the use of this form of the invention, the hose will he swiveled in the mounting connection therefor at the top of the cleaner to allow the operator freedom to assume any angular position with respect to the cleaner in the use of the dusting tool. When the operator desires to move the cleaner from place to place, the arm 175 is actuated from the position illustrated in Figures 5 and 6 whereupon the air cushion or air bearing is formed and the operator may move the cleaner about with response to a very slight pull upon the flexible suction hose. When the cleaner has been moved to the desired position, the arm 175 is actuated to restore the parts to the position 55 illustrated in Figures 5 and 6 and the cleaner is again in operation without significant back pressure and with the exhaust diffuser and director functioning to prevent blowing of loose material about the carpet and to prevent the development of back pressure on the cleaner.

In each form of my invention the cleaner is characterized by the provision of a supporting structure constructed and arranged to receive exhaust air from the power plant of the cleaner and to cause such air to be entrapped in a plenum chamber and to build up in pressure until the weight of the cleaner is counterbalanced and is supported upon an air cushion or hearing to provide ease of movement about a supporting surface. In addition to the foregoing, the cleaner structure is provided with a valve control exhaust directly to the atmosphere whereby the exhaust air is normally passed through a low resistance diifuser and returned to the atmosphere without forming an air supported bearing for the cleaner; the control valve structure is actuated by the operator at will to change the cleaner from the air supported to the non-air supported condition.

While I have illustrated and described the invention in considerable detail, it is to be understood that various changes may be made in the arrangement, proportion and construction of parts without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a suction cleaning apparatus having a casing, a filter in the casing, a suction nozzle connected to the easing, a suction producing unit in the casing arranged to produce a flow of air through the nozzle and filter and to discharge such air into the casing under pressure, an exhaust structure for conducting such air under pressure from the casing to the atmosphere including a port in the wall of the casing and a member adjacent the casing having a port therethrough, means for producing relative motion between the casing and member to move the ports into and out of registry for allowing or preventing fiow of air through the exhaust structure, a supporting structure including surface engaging means encompassing a substantial area between the supporting surface and the underside of the casing, and means for conducting such air under pressure from the casing to the said area whereby air pressure will be applied to the said area sufficient to support the cleaner on an air bearing when said ports are moved out of registry.

2. Apparatus according to claim 1 wherein said member movably mounts the casing on the supporting structure, spring means acting between the casing and member normally biasing the casing to a position in which the ports are in registry, and a flexible suction hose interposed between the suction nozzle and easing whereby a tug applied to the hose moves the casing on the member to shift the ports out of registry and to establish an air bearing support for the cleaner.

3. Apparatus according to claim 1 wherein the member is rotatably mounted on the casing and manually operated means are provided for shifting the member into and out of registry.

4. Suction cleaning apparatus comprising a generally spherical housing, a supporting structure for the housing having a surface engaging portion encompassing a substantial area on the underside of the housing and open to a supporting surface, a generally spherical casing mounted within the housing for movement relative thereto, a filter in the casing, a suction nozzle, a hose connected to the nozzle and to the casing to direct air and entrained dirt into the filter, a suction producing unit in the casing arranged to produce a flow of cleaning air through the nozzle and hose into and through the filter and to discharge such air under pressure, the casing and housing having closely adjacent spherical sections, a plurality of circular air ports in the casing spherical section centered on a circle and spaced apart on the circle a distance greater than their diameter, matching ports in the housing spherical section opening to the atmosphere, and means biasing the casing to a position within the housing in which the ports are in registry.

S. In a suction cleaning apparatus having a casing, a filter in the casing, a suction nozzle connected to the easing, a suction producing unit in the casing arranged to produce a flow of cleaning air through the nozzle and filter and to discharge such cleaning air under pressure, the combination of a supporting structure for the casing having a surface engaging member enclosing a substantial area between the casing and a supporting surface, means for conducting air under pressure from the suction producing unit to the said area, and means forming a vent passage leading from said area to the outside of said casing and means for closing said vent passage so as to build up a pressure in said area sufficient to support the cleaner on a cushion of air.

6. Suction cleaning apparatus comprising a casing housing a filter and suction creating means and having an exhaust chamber into which air is discharged from the suction creating means, a supporting structure having an annular surface engaging part and forming an air chantber between the supporting surface and the underside of the cleaner casing, means forming a first exhaust port from the exhaust chamber to the air chamber, means forming a second exhaust port from the exhaust chamber to the atmosphere and valve means for controlling the flow of air through the second exhaust port whereby an air pressure may be built up in said chamber sutficient to support the cleaner on an air cushion by closing said second exhaust port.

7. Suction cleaning apparatus comprising a housing, a filter in the housing, a suction creating means in the housing, a support for the housing having a peripheral portion encompassing a substantial area beneath the housing, means for conducting exhaust air from the housing into a zone beneath the housing within the perimeter of the support, and valve controlled means for conducting exhaust air directly from the housing to the atmosphere whereby all of the exhaust air is led to said zone when the said valve controlled means is closed so as to build up an air pressure in said zone sufficient to support the cleaner on an air cushion.

8. Suction cleaning apparatus comprising a cleaner casing housing a filter and a suction producing unit, a supporting structure for the casing having a surface engaging portion encompassing a substantial area and forming a plenum chamber between said casing and a supporting surface, means for conducting exhaust air from the suction producting unit to said plenum chamber on the underside of the cleaner, an exhaust structure for conducting exhaust air directly from the suction producing unit to the atmosphere including means for preventing air flow therethrough, and manually operated means for controlling the flow of air from the exhaust structure to the atmosphere.

9. In a suction cleaner having a casing, a suction cleaning nozzle and an air pump connected to draw cleaning air through the nozzle into the casing and to discharge such cleaning air under pressure, the combination of a supporting member for the casing having a substantial perimeter enclosing an area on the underside of the casing open to the supporting surface so as to form a plenum chamber between said casing and the supporting surface, means for conducting air discharged from the air pump to said plenum chamber whereby such air under pressure supports the casing on an air cushion and air escapes under the perimeter of the supporting member, and means forming an exhaust structure including a manually controlled valve for conducting exhaust air from the air pump directly to the atmosphere.

10. In a suction cleaner having a casing, a suction cleaning nozzle and an air pump connected to draw cleaning air through the nozzle into the casing and to discharge such cleaning air under pressure, the combination of a supporting member for the casing having a substantial perimeter enclosing an area on the underside of the casing open to the supporting surface and forming a plenum chamber between said casing and the supporting surface, means for" conducting air discharged from the air pump to the said plenum chamber whereby such air under pressure supports the casing on an air cushion and air escapes under the perimeter of the supporting member, a plurality of exhaust ports in the casing for conducting air under pressure from the air pump directly to the atmosphere, a member mounted to move relative to the casing for opening and closing the exhaust ports, and manually actuable means for controlling relative movement between the casing and membetx l1. Suction cleaning apparatus comprising a casing, a filter in the casing, a suction hose connected to the casing to discharge into the filter, a suction producing unit in the casing arranged to draw air through the hose and filter and to place such air under pressure, a supporting structure for the casing including means defining an air chamber between the underside of the casing and a supporting surface, an air duct on the casing for conveying air under pressure from the suction producing unit to the air chamber, the casing and supporting structure each having concentric closely adjacent spherical sections, means on the supporting structure for supporting the casing thereon for rocking movement about the center of the spherical sections, port means in the spherical section of the supporting means open to the atmosphere, port means in the spherical section of the casing adapted to register with the port means in the spherical section of the supporting means to discharge such air under pressure therethrough, means biasing the casing to a position in which the port means are in registry, the port means in the casing and support means being spaced apart a dis tance greater than the maximum dimension of the port means whereby a pull on the hose will rock the casing on the support means to move the two port means out of registry and air under pressure discharging through the air duct supports the cleaning apparatus on an air cushion or bearing.

12. A suction cleaner comprising, a casing having an inlet port and an exhaust port, a fan unit within said casing for drawing cleaning air into said casing through said inlet port and discharging it under pressure through said exhaust port, a support for said casing including an annttlar surface engaging member forming an air trapping pocket open to said exhaust port and to a supporting surface whereby air under pressure discharged through said exhaust port will build up a pressure Within said pocket sufficient to support the cleaner on a cushion of air, means forming a vent passage leading from said pocket to the outside of said casing and manually actuatable means for selectively opening and closing said vent passage whereby the air pressure within said pocket may be selectively maintained to air support the cleaner or released whereby the cleaner is supported directly on said annular surface engaging member.

References Cited in the file of this patent UNITED STATES PATENTS 955,886 Laughlin Apr. 26, 1910 963,139 Grifiiths July 5, 1910 1,083,408 Matchette Jan. 6, 1914 1,817,337 Baker Aug. 4, 1931 2,332,208 Dow Oct. 19, 1953 FOREIGN PATENTS 116,431 Great Britain June 13, 1918 584,997 France Dec. 1, 1924 1,038,655 France May 13, 1953 

